Looks like a job for mod_rewrite and .htaccess.
See, unless you tell your webserver differently, "www.domain.com/in.php/x/y/" tells the server to go to go to directory "in.hp" then the subdirectory "x" and then the subdirectory of "y." You'll probably end up with a 404 page not found error. You definitely can give it a whirl and see for yourself. To wiggle around this problem, you can use Apache and mod_rewrite with .htaccess and specify the URL rules to do this. Search this forum or google and you'll find a TON of info on this.